Health and safety issues are a constant concern for mining companies operating underground mines. Hundreds of miners work underground daily in an environment where air quality is strictly regulated. Because substantially all underground vehicles travelling in mine drifts run with combustion engines, and since a high number of them are in operation concurrently, exhaust emissions from these vehicles represent an important polluter. It is therefore critical to properly maintain these diesel engines to avoid undesirably high emissions of gases such as carbon monoxide, nitrogen dioxide, nitrogen oxide, carbon dioxide, and the like. Controlling these emissions, or at least having a better knowledge of what they are, will have a direct beneficial impact on the mine ventilation requirements, which is one of the most expensive operating cost for underground mining, as well as on the health of the miners.
The monitoring of diesel exhaust emissions in underground mining environments has in the past been a somewhat less than exact science. Due to lack of understanding, lack of precision instruments for measuring emissions in the work environment, and lack of a common testing method, this critical component of mine operations has been left underdeveloped. Diesel exhaust emissions have consistently posed the problem of understanding what actually is coming out of the tailpipe of a diesel engine at any given time. Understanding and monitoring these emissions can improve the performance and maintenance of engines, and therefore bring the emissions to safer and healthier levels.
U.S. Pat. No. 4,328,546 is concerned with an automated engine diagnosing device using, among other things, a digital data processor. One of the objectives of this device is to display to the operator emissions data accumulated from a vehicle engine in an easy-to-understand form for facilitating automotive repairs. Another objective is to visually display to the operator an indication of the concentration of engine emission gases occurring in accordance with the efficiency of firing of a selected cylinder of the engine. Analyzers suitable for the purpose of this invention include those available for analyzing gases like carbon monoxide, nitrogen dioxide, nitrogen oxide, carbon dioxide, oxygen, etc. However, the method involves injecting individual cylinder faults only, and emissions based on a per cylinder basis. Further, the data acquisition and analysis is based on one peak value per engine cylinder. Finally, there is no mention or description of advanced data storage and analysis capabilities in the system.
It would therefore be highly desirable to develop a system to perform exhaust tests for tracking individual engine emissions by using a total engine state load factor. Such system would allow verification of engine maintenance and repairs, and further evaluation of exhaust after-treatment instruments. The method of use of such system should also be standard so that it can be applied to any type of combustion engine. Such system and method should also preferably allow the measurement of the gas temperature and pressure in the exhaust system.